This invention relates generally to a convertible dock ramp and stair assembly and more particularly to a convertible dock ramp which can be selectively place in a ramp configuration or a stair configuration.
It is often necessary to provide a bridging structure between two other structures, one of which is floating. For example, a gangway may be provided between a ship and a fixed dock, or a ramp may be provided between a fixed pier and a floating dock. As the water level rises or falls, the floating structure changes its height relative to the fixed structure, and accordingly the angle of the bridging structure relative to a horizontal reference plane changes.
A ramp-like structure is easier to traverse a relatively low angles, while a stair-like structure is easier to traverse at more steep angles. In the prior art, this fact is often accommodated by providing a bridging structure having pivotable stair treads which can remain level as the angle of the overall structure changes. Some of these units allow the treads to move into a position creating a ramp at very low angles. While these units provided the desired adjustability, they freely convert from one configuration to the other regardless of a user's wishes. Such units cannot be controlled from a remote location and can therefore be inconvenient. Furthermore, such units can create a safety hazard if a person's foot should be positioned between the stair treads as the unit is moving towards a ramp configuration.